Introduce array textures for node rendering (#16574)

client/shaders/inventory_shader/opengl_vertex.glsl

@@ -0,0 +1,27 @@
+varying vec3 vNormal;
+varying vec3 vPosition;
+#ifdef GL_ES
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
+varying float varTexLayer;
+#else
+centroid varying vec4 varColor;
+centroid varying vec2 varTexCoord;
+centroid varying float varTexLayer; // actually int
+#endif
+
+void main(void)
+{
+#ifdef USE_ARRAY_TEXTURE
+	varTexLayer = inVertexAux;
+#endif
+	varTexCoord = inTexCoord0.st;
+
+	vec4 pos = inVertexPosition;
+	gl_Position = mWorldViewProj * pos;
+	vPosition = gl_Position.xyz;
+	vNormal = inVertexNormal;
+
+	vec4 color = inVertexColor;
+	varColor = clamp(color, 0.0, 1.0);
+}